In connection with aircraft such as helicopters, it is important to train pilots and maintenance personnel in the various operational, maintenance and service aspects of the aircraft and its systems. It is known to prepare various mockup and demonstrative apparatus and displays, sometimes of a reduced scale and frequently not to any scale, of the structure or systems of the aircraft.
Fuel system training apparatuses are utilized to provide practical experience in the operation, maintenance practices and fault isolation techniques of aircraft fuel systems. They are particularly useful for teaching the operation of aircraft fuel systems because the entire system is recreated with actual components which are located and operated the same as in the aircraft. Exemplary tasks for which the fuel training systems are utilized are instruction on refuel probe control, pressure refueling, defueling, fuel transfer, dumping, mission fueling, purging, fuel quantity indicating, engine fuel supply/priming, trouble-shooting, component removal/insulation, calibration and rigging.
Training apparatuses are designed to resemble the actual fuel containment and transfer systems of the applicable aircraft. Thus, they duplicate as closely as possible the actual conditions and systems that exist on an aircraft. Typically, a fuel training apparatus comprises at least two fuel tanks or cells connected by fuel lines and pumps for transferring the fuel between the tanks. In addition, the fuel system contains the visual indicators, switches, hardware and components necessary to accurately simulate the fuel system.
In order to closely simulate onboard fuel systems, conventional fuel training systems utilize actual aircraft fuel. This, for example, results in an accurate duplication of fuel transfer rates. However, the use of this fuel while desirable, has been found to be disadvantageous because of its relatively low flash point and particularly because of its odor. The low flash point creates a safety problem and in classrooms the odor is distracting and disturbing to many persons. Because of the fire and odor problems with state-of-the-art aircraft fuel system training equipment, there is a considerable amount of such equipment, representing many thousands of dollars, which is stored or has limited use because of the danger to personnel.